There is a seven-year war, Russian soldiers are forced to fight for the interests of France and Austria against Prussia. The midshipmen continue to selflessly serve the Motherland. One is on an expedition, the other is at court, and the third is sent to Venice to hand over a jewelry box. In fact, there is a message in the box, on which the future fate of Europe and Russia depends!

These are the dark times around 1720 in Russia. Tsar Peter the Great dies and his highly esteemed partner and friend Prince Menshikov rules the country from now on. But there are also those who oppose the prince. Messenger Ivan, an army officer, fails one of the risky resistance orders given to him by the scheming opposition and openly confesses to it. He is to be punished mercilessly, but the head of the secret service recognizes the officer's qualities, and from now on Ivan becomes an agent of the Tsar. Thus begins a series of mysterious incidents and he begins to investigate them. Masons, pirates and grand dukes, all have their dark secrets...

These are the dark times around 1720 in Russia. Tsar Peter the Great dies and his highly esteemed partner and friend Prince Menshikov rules the country from now on. But there are also those who oppose the prince. Messenger Ivan, an army officer, fails one of the risky resistance orders given to him by the scheming opposition and openly confesses to it. He is to be punished mercilessly, but the head of the secret service recognizes the officer's qualities, and from now on Ivan becomes an agent of the Tsar. Thus begins a series of mysterious incidents and he begins to investigate them. Masons, pirates and grand dukes, all have their dark secrets...

Russia in the early 18th century: Naval officer Plakhov has fallen in love with a young woman. When she is threatened by a stranger, he kills him and is thereby sentenced to death. However, the head of the secret service decides to send Plakhov on a mission instead.